Textile yarn winding machine with anti-patterning device

ABSTRACT

TO PREVENT UNDESIRABLE PATTERNING ON THE CONE AND TO PROVIDE FOR SLIP BETWEEN THE YARN PACKAGE AND THE GROOVED TRAVERSE DRUM THEREFOR, THE SPEED OF THE GROOVED DRUM IS VARIED BY INTERMITTENTLY INTERRUPTING THE DRIVE TO THE DRUM UNDER CONTROL OF AN ELECTRICAL SWITCH WITH PERIODICALLY   INTERRUPTS THE POWER SUPPLY TO THE MOTOR, THE PHASING OF INTERRUPTION WITH RESPECT TO THE PHASE OF SUPPLY CURRENT BEING CONTROLLED IN DEPENDENE ON THE LOAD OF THE MOTOR.

March 20, 1973 W RFFEL 3,721,877

TEXTILE YARN WINDING MACHINE WITH ANTI-PATTERNING DEVICE Filed April 19, 1972 2 Sheets-Sheet 2 Fig. 3 Us t F lg. 2 n mu l/\ 1 a min \J L t t t Fig, 4 t U? U 2- 2M t J Fug. 6

United States Patent Oflice 3,721,877 Patented Mar. 20, 1973 3,721,877 TEXTILE YARN WINDING MACHENE WITH ANTl-PATTERNING DEVICE Herman Werlteli, Horgen, Switzerland, assignor to Maschinenfahrik Schweiter A.G., Horgen, Switzerland Filed Apr. 19, 1972, Ser. No. 245,458

Claims priority, application Switzerland, Apr. 23, 1971,

5,977/71 Int. Cl. 1102p /16 US. Cl. 318-318 9 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a textile yarn winding machine for winding of yarn packages, in which a plurality of spindles for the yarn packages are associated with commonly driven grooved patterning drums, and more particularly to such a textile machine which is provided with an anti-pattern device to provide high cone quality and to prevent formation of undesirable patterning as the spool or yarn package is being formed.

It has previously been proposed to intermittently, rapidly interrupt the drive to the grooved drum over which the yarn passes during formation of the spool or yarn package, in order to prevent a patterned winding from being wound on the yarn. The slip between the package and the grooved drum is constantly changed, and thus the direct proportionality, based on whole numbers, between the effective circumference of the grooved drum and the package is distorted. This distortion prevents formation of a patterned package. One form of anti-patterning arrangement utilizes relays which intermittently interrupt three-phase power to a three-phase motor. The ON time of the relay must be selected to be sufficiently large so that the motor reaches its nominal speed. This has the disadvantage that the relays are subjected to substantial wear; further, the apparatus is highly dependent on variations of supply voltage and load, and there is substantial time delay between the various ON-OPF cycles. It is difficult to eiiectively prevent formation of a pattern on the cone.

Mechanical means to vary the speed of the drum, such as variable speed drives utilizing V-belts, and providing varying speeds cyclically changing from a center value are subject to similar difficulties.

It has been proposed to provide a direct current motor to drive the grooved patterning drum and, by means of an electronic interrupting circuit, to disconnect the direct current motor in uniformly recurring cycles, the average speed of the motor being controlled by voltage regulation of the supply thereto. Besides the higher maintenance required for D-C motors, it is difiicult to maintain the average speed constant due to changes in loading on the motor as well as due to supply voltage variations.

It is an object of the present invention to provide a textile spooling or winding machine, which may be referred to as a coner to make textile cones or yarn packages, and which, independently of changes in loading, or voltage variations of supply elfectively prevents undesirable patterning on the cone during formation of the cone.

SUBJECT MATTER OF THE PRESENT INVENTION Briefly, the drive to the grooved patterning drums is intermittently interrupted, in order to prevent formation of undesirable patterning on the cone by providing a bistable electric switch which responds to minimum and maximum speeds, as determined by a control, the output of the electronic switch being connected to the phase switches of the motor and, further, over a circuit which is responsive to the loading of the motor, which circuit controls the phasing of the ON-time of connection of the motor so that the ON-time of the motor itself will be maintained constant in spite of variations of the loading thereon.

In a preferred form, phase shift circuits are provided, connected to each one of the phase supply switches (which may be solid state and are in the form of controlled switches). The phase shift is controlled by the difference in pulses commanded by a pulse generator and the actual ON-time of the pulses derived from the output of the bistable switch, to thereby provide a control signal which can change the phasing of the ON-time of connection of the motor with respect to the power supply.

The invention will be described by Way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a circuit diagram of the drive for the grooved drum of the textile coning or spooling machine; and

FIGS. 2-6 are graphs used in connection with the description of the operation of the circuit of FIG. 1.

The grooved drum, not shown herein and known as such, and the drive therefor for a coning or textile spooling machine, (also known) is effected by motor M, connected to a three-phase supply 10, having phases R, S, T.

Motor M is mechanically connected to a tachometer generator T which provides an output signal representative of instantaneous actual motor speed. This output signal is applied to a summing network 11. The other input to the summing network 11 is connected to the tap point of a potentiometer 12 which provides a command voltage, the value of which is determined by the setting of the potentiometer 12. Potentiometer 12 itself is supplied from a source 13 of stabilized voltage.

The reference or command voltage 12, and the motor speed signal derived from tachometer generator T are subtracted from each other to form a difference value. This signal is applied to a bistable switch 16, in form of a flip-flop, over a pair of parallel connected threshold switches 14, 15. Threshold switches 14, 15 may well be Schmitt triggers. Threshold switch 14 is set to provide an output when the signal from tachometer generator T reaches an upper speed value, representative of a maximum speed n Threshold switch 14 provides an output signal when the speed of motor M reaches a lower threshold value 11 as will be described in detail below. If a signal is derived from the threshold switch 14, flipflop 15 is triggered to provide an output signal therefrom which will control solid-state switches R17, S17, T17 to interrupt power supply to the motor M. It a signal is derived from threshold switch 15, however, the flip-flop 16 will change state and trigger the solid-state switches R17, S17, T17 to again connect the power supply 10 to the motor M. The solid-state switches R17, S17, T17 which interconnect the power supply 10 and the phases R, S, T to the motor M may be in form of a triac; the trigger electrodes of the triacs are controlled by trigger networks R18, S18, T18, connected to the output of flip-flop 16. The triacs themselves are, essentially, a pair of counterparallel connected thyristors, one each of the positive and negative half waves of the respective phases.

The connecting period, or duration of the bistable switch 16 should be held constant regardless of load on the motor; thus, circuit means are provided to control the motor torque in dependence on loading thereon. These motor torque control means include phase shifters R19, S19, T19, connected in series and in advance of the trigger or firing pulse generators R18, S18, T18 respectively. A first input of each phase shift circuit is connected to the output of the flip-flop 16; a further input of each phase shift circuit is connected to the output of an integrator 20. A third input of each phase shift circuit is connected to a synchronizing line R, S, T, respectively, which connects with the respective phases R, S, T to supply a signal to the phase shifters when each voltage wave of the power from source goes through zero, or null.

Integrator 20 is connected in series with a gate 21, in form of a NAND-gate, which has one input connected to the output of the flip-flop 16; the other input is connected to the output of a pulse generator 22 which is triggered from the output of the lower threshold circuit 15, by being connected to its output. A discharge or leakage resistor 23 bridges the integrator 20.

It is only necessary to control the time duration t (FIG. 2) of the motor during which the motor is connected, that is, during acceleration of the motor, since torque has to be generated which should be independent of voltage variations from the supply line and which is sufficient to overcome the variable sum of all the single masses, and single resistances and loads of the various spools of a multiple spindle spooling or coning machine. The delay time, during the OFF period of connection of the motor from the supply or network 10, that is the time t (FIG. 2) can be assumed to be essentially constant. Threshold switch 14 responds when the upper speed n is exceeded; threshold switch responds when a lower speed n is passed, the switches, of course, responding to electrical signals from the tachometer generator representative of the respective minimum and maximum speeds. The first line of the graph of FIG. 2 illustrates this variation as a function of time. Upon appearance of a signal as threshold switch 15, a voltage U will appear at the output of flip-flop 16, until threshold switch 14 responds. The pulses of voltage U are seen in the second line of the graph of FIG. 2. It is apparent that, without further controls, the duration or length 2, of the switching-on pulses U will depend on the loading on the motor. For example, if the motor is highly loaded, a longer period of time t, must pass until the motor reaches a speed n than if the motor were only lightly loaded.

To make the cyclical ON-OFF period of the motor uniform, each ON pulse of the threshold switch 15 is applied to a pulse generator 22, which provides a pulse of a command value t to effect acceleration of the motor M from a lower speed value n to the upper speed value n The output pulses U derived from the output of pulse generator 22 (triggered by the threshold switch 15) will have a pulse duration t and are seen at graph U in the third line of the diagram of FIG. 2.

The actual time pulses U of time duration t and the command pulses U of time duration t are applied to gate 21, which provides an output or difference pulse U of time t This pulse is seen in the fourth line of the diagram of FIG. 2, and applied to the integrator 20. Integrator will store and integrate the difference pulses U of time duration t and provide an output voltage U This output voltage will drop from the preceding level during the intervals between succeeding pulses U of time t due to the presence of the leakage resistance 23. The output voltage U, from integrator 20 is used a a control voltage for the phase shifters R19, S19, T19. These phase shifters control the trigger or firing pulse generators R18, S18, T18 to provide the trigger pulses for the triacs R17, S17, T17, respectively, and to phase shift the trigger pulses with respect to the line power supply from source 10 by a predetermined phase angle a. As seen in FIGS. 3 and 4, the phase angle 11 should increase with respect to the phase angle a when the actual time duration I, of pulses U is greater, due to increasing loading on the motor, than the commanded time t of pulses U Thus, by increasing the phase angle of connection, that is, by increasing the connection time of the motor to the power network, the torque M of the motor M is increased and the motor will reach the upper speed limit n in spite of increasing loading thereon within the desired period of time, to be then again disconnected by response of the maximum-level threshold switch 14. Thus, the required short-term, cyclical and uniformly repetitive interruption of the grooved drum is obtained to prevent undesirable patterning on the cone, while maintaining a constant average speed. FIG. 5 illustrates the dependence on the start-up torque M on the integrated voltage U.,, and the phase angle a of current flow. As the acceleration period of actual value t approaches the commanded acceleration value t or even becomes less than the commanded value t the phase angle during which current can flow, that is angle or decreases. Integrator 20 will not have fresh pulses U (FIG. 2) applied and the integrator voltage U; will decrease by discharging over the leakage resistance 23.

FIG. 6 illustrates the control of the motor start torque in dependence on loading to maintain the ON-time of the motor constant, over a number of cycles, that is, over a substantial period of time. During the period a, as seen from the difference pulses i the actual time t, of the pulses from flip-flop 16 is greater than the command time 1 of the pulses from generator 22, as set into the generator. Thus, the start torque of the motor must be increased. This is accomplished, as clearly seen by the rise of the voltage U,,, which will in effect control the triacs to increase the phase angle during which power is connected to the motor. As described above, this voltage U; controls the phase shifters R19, S19, T19 in such a direction that the phase a FIG. 4, is increased. The required torque from the motor, and the load on the motor are essentially in balance during the period b of the diagram of FIG. 6; the voltage U, remains essentially uniform, and the pulses U likewise are of essentially uniform time duration. If, for example, some of the winding positions of the multiple spindle winding machine driven by the motor are disconnected, that is, if the loading on the motor is decreased, then the acceleration torque of the motor will be too great, so that the actual time t of the response of threshold switch 15 when the speed n (FIG. 2) is reached will be too short with respect to the commanded time t Gate 21 can no longer provide a difference pulse of a time t and the control voltage U, on the integrator 20 decreases, by discharge over resistance 23, as seen in the section 0 of FIG. 6. The phase angle during which current can flow, that is m in FIG. 3 decreases, thus decreasing the acceleration torque of the motor. This, in turn, increases the turn-on time t of the bistable switch 16 with respect to the command t The cycle will repeat until, again, balance is effectively achieved, as seen in section d, FIG. 6, where, after the loading has again increased, voltage U; also again increases.

Various changes and modifications may be made in the apparatus in accordance with the inventive concept.

The apparatus to which the present invention relates is described as a whole, for example, in publication Schweiter Precision Cone Winders, and particularly with reference to model CA 11, circular automatic coner with ten winding heads on a revolving circular table, publication CA 471e, Schweiter Engineering Works Limited, Horgan, Zurich (Switzerland). The invention, of course, is equally applicable to other cone winding textile apparatus, the foregoing being merely one example of its use.

What is claimed is:

1. Textile yarn winding machine for winding aplurality of yarn packages and having a common motor (M) in which the motor is energized from an A-C source (10) comprising controlled switch means (R17, S17, T17) interconnecting the source (10) and the motor (M); a bistable switch (16) and control means (R19, S19,

T19) interconnecting the bistable switch and the control input of the controlled switch means;

means (T; 12, 13) generating a motor speed control signal; threshold switch means 14, 15) connected to and controlled by said motor speed control signal and providing an output signal to control switch-over of the bistable switch (16) in dependence on the motor speed control signal reaching an upper, or lower threshold level, respectively; and load responsive means (20, 21, 22) interconnecting the output of the bistable switch (16) and the control means (R19, S19, T19) and being responsive to loading of the motor to adjust the phasing of the controlled switch means with respect to the phase of said source to maintain the ON-time of the bistable switch at a constant value. 2. Machine according to claim 1, wherein the control means comprises phase control means (R19, S19, T19) which change the phase angle of current flow (a);

and the load responsive means comprises a pulse source (22) providing command pulses (U of duration (t representative of a phase angle of connection of the motor to the source required to cause the motor to increase speed, and comparator means (21) having said command pulses applied thereto and the output pulses (U from said bistable switch 16) and having a duration (t representative of phase angle of connection of the motor as determined by actual motor speed, said comparator means (21) providing a difference output signal (U of duration (i representative of the difference (I -t of the duration of said command pulses (U and said bistable switch pulses (U said difference pulses (U controlling the phase control means (R19, S19, T19).

3. Machine according to claim 2, wherein the comparator means (21) comprises a gate.

4. Machine according to claim 2, wherein said load responsive means comprises an integrator (211) to store and integrate the difference output signal (U and pro vide an integrated output (U said integrated output being applied to the phase control means (R19, S19, T19).

5. Machine according to claim 4, further comprising a leakage resistance (23-) bridging the output of the integrator (20).

6. Machine according to claim 2, further comprising a synchronizing line (R', S, T) interconnecting the phase control means (R19, S19, T19) and the source to synchronize the phase control means with the power supply as the voltage of the power supply passes through zero.

7. Machine according to claim 1, wherein the means generating a motor speed control signal comprises a reference source (12, 13);

signal generator means (T) providing an output signal representative of motor speed;

and comparator means (11) comparing the actual motor speed signal and the output of the reference source and providing a difierence signal, said difference signal forming said speed control signal being applied to said threshold switch means.

8. Machine according to claim 1, comprising a synchronizing line (R', S, T) interconnecting the phase control means (R19, S19, T19) and the source (10) to synchronize the phase control means with the power supply as the voltage of the power supply passes through zero;

and wherein the load responsive means comprises a pulse source (22) providing command pulses (U of a duration (t representative of a phase angle of connection of the motor to the source with respect to the phase of the power supply as required to cause the motor to increase speed or torque, and comparator means (21) having said command pulses applied thereto and the output pulses (U from said bistable switch (16) as controlled by said threshold switch means (14, 15) and having a duration (t representative of phase angle of connection of the motor as determined by actual motor speed, said comparator means providing a control output signal (U of duration representative of the difference (t t of the duration of said command pulses (U and said bistable switch pulses (U said difference pulses controlling the phasing of the connection of the motor to said source by controlling the phase control means (R19, S19, T19) connected to said controlled switch means (R17, S17, T17).

9. Machine according to claim 8, wherein said load responsive means comprises an integrator (20) to store and integrate the difference output signal supplied by said comparator means (21) and providing an integrated output (U said integrated output being applied to control the phasing of said phase control means (R19, S19, T19).

References Cited UNITED STATES PATENTS 3,413,534 11/1968 Stringer 318*345 3,445,742 5/1969 Moscardi 318341 3,579,065 5/1971 Laukaitis 318'341 3,596,162 7/1971 Takayama 318-341 BERNARD A. GILHEANY, Primary Examiner T. LANGER, Assistant Examiner US. Cl. X.R. 318-327 

